Hearing aids are very small and delicate devices and comprise many electronic and metallic components contained in a housing small enough to fit in the ear canal of a human or behind the outer ear. The many electronic and metallic components in combination with the small size of the hearing aid housing impose high design constraints on radio frequency antennas to be used in hearing aids with wireless communication capabilities.
Moreover, the antenna in the hearing aid has to be designed to achieve a satisfactory performance despite the limitation and other design constraints imposed by the size of the hearing aid.